The goal of this proposal is to provide new technical skills and rigorous academic training to launch the principle investigator's independent research career. The long-term goal is to understand molecular mechanisms modulating sympathetic nervous system (SNS) function, leading to new treatments for pathophysiological SNS activity. In addition, investigations into genetic causes of SNS dysfunction (dysautonomia) will be initiated. The SNS functions as an integrative peripheral nervous system to regulate vital organ function, in part by release of catecholamines (CA). Disease states as varied as Parkinson's disease and sepsis can lead to dysfunction of the SNS and patient morbidity. Feedback modulation of CA release occurs by activation of a2A and a2c adrenergic receptors (ARs) on sympathetic neurons. Neuropharmacological differences between these two autoreceptors are not completely known, thus limiting development of specific drugs for disease treatment. The proposal will test the hypothesis that protein motifs within a2A&c ARs and their interacting proteins are responsible for differential trafficking in neurons, leading to distinct functional roles as modulators of CA release. The specific aims of this proposal include 1) delineation of a2A&C AR motifs and their interacting proteins, 2) single cell amperometric analysis of a2A&c AR modulation of CA release, and 3) investigation of known a2A&c AR genetic variants. Knowledge gained in this system should be applicable to other neuromodulator systems such as opiate and cannabinoid receptors. This proposal describes a 5-year training program to initiate an investigation into the SNS. The principal investigator has completed residency and fellowship training in Anesthesiology and Critical Care Medicine, as well as a Ph.D. in Pharmacology and postdoctoral studies in Germany. This proposal will assist his training to pursue a career as an independent investigator on the Clinician Scientist track at Stanford University, in part by reducing his clinical patient care commitment to 20-25%. The proposal will be guided by Dr. Brian Kobilka, a leading expert in adrenergic receptor biochemistry and physiology, who has trained several post-doctoral fellows and clinician scientists. An Advisory Committee of pharmacologists and neuroscientists will provide scientific and career advice and training in the techniques of amperometry and SNS cell culture required for this project's success.